"Going out in winter without a hat is like a thermos without a lid." This folk saying vividly describes the importance of keeping the head warm. In the cold winter, about one-third of the body's heat is dissipated through the head; when the temperature drops to around 4°C, about half of the heat is lost from the head. Keeping the head warm is not just a simple measure against the cold, but a health barrier to prevent various diseases. It is especially important for special groups such as the elderly and children, as their temperature regulation mechanisms are more fragile, and a cold head can trigger more serious health problems.

I. Why is the head a key area for staying warm in winter?

Although the head accounts for only about 7% of the body's surface area, it is a "disaster area" for body heat loss. This is closely related to the head's unique physiological structure. The head is rich in blood vessels, and the ratio of blood flow to surface area is 4 to 10 times that of the torso and proximal limbs. More importantly, unlike other parts of the body, the blood vessels in the head do not constrict under cold stimulation, leading to continuous heat loss. This physiological characteristic makes the head the primary channel for body heat dissipation.

Scientific research shows that the proportion of heat loss from the head at different temperatures is staggering. In an environment of 15°C, when at rest without a hat, about one-third of the body's heat will dissipate from the head; when the temperature drops to around 4°C, about half of the heat is lost from the head. This proportion of heat loss is much higher than the head's share of the body's surface area, fully demonstrating the importance of head warmth. In addition, the skin on the head is thin and the blood vessels are densely distributed, acting like an "open radiator" that dissipates heat more easily in cold environments. Therefore, wearing a hat in winter is like putting a "thermos plug" on the body, which can effectively reduce heat loss and maintain a stable body temperature.

II. Why do the elderly need head warmth even more?

As people age, their ability to regulate body temperature declines significantly. Numerous studies have shown that normal body temperature decreases slightly with age, and the body temperature of those over 65 is often lower than the average for the general population. This characteristic of lower body temperature makes the elderly more sensitive to the cold, and the impact of cold exposure to the head is even more severe.

Cold exposure to the head in the elderly can directly trigger cardiovascular and cerebrovascular diseases. Cold stimulation activates the body's sympathetic nervous system, leading to vasoconstriction, elevated blood pressure, and increased cardiac load. For every 1°C drop in temperature, the mortality rate related to cardiovascular disease increases by 1.6%, and the incidence rate increases by 1.2%. Especially for elderly people with underlying conditions such as arteriosclerosis and hypertension, a cold head can act as a "fuse" that triggers myocardial infarction or stroke.

The winter health guidelines released by the Shanghai Municipal Health Commission explicitly state: "The elderly should pay attention to keeping warm and add clothing appropriately based on perceived temperature. It is recommended to use air conditioning and heating during cold weather. When the environment changes, be careful to avoid excessive temperature differences when entering or leaving spaces. Drastic temperature changes within a short period can easily induce cerebrovascular accidents." This indicates that authoritative institutions also recognize the importance of head warmth for the health of the elderly.

III. Special requirements for keeping children's heads warm

The need for head warmth in children is equally impossible to ignore. A child's head accounts for a relatively large proportion of their total body weight; an infant's head weight is equivalent to half of their total body weight, while the head weight of 3-year-olds and 6-year-olds accounts for 18% and 16% of their total body weight, respectively. This means that children have a higher proportion of heat dissipation through the head and are more sensitive to the cold.

Furthermore, children's immune systems are not yet fully developed, resulting in weaker defensive capabilities. Exposure to cold at the head can cause the "defense outposts" of the nasal mucosa to fail, allowing viruses to invade easily. This explains why children are more prone to colds in winter. According to the cold index released by the China Meteorological Administration, the incidence of colds increases significantly when the temperature is around 10°C and the temperature difference exceeds 10°C. Moreover, children are often not sensitive enough to perceive temperature changes and may not take timely measures to keep warm even when they feel cold.

Children have a denser distribution of blood vessels in the head and more active blood circulation, which makes heat loss from the head more likely. Furthermore, because a child's neck is not yet fully developed and the muscles and ligaments are not completely formed, insufficient warmth for the head can lead to more serious health issues. Therefore, when children go out in winter, wearing a hat is not only a requirement for warmth but also a necessary measure for health protection.

4. Four Major Health Benefits of Wearing a Hat

1. Preventing Cardiovascular Diseases

Cold stimulation causes blood vessels to constrict, increasing the burden on the heart. Wearing a hat can reduce heat loss from the head and lower the magnitude of blood pressure fluctuations. Research shows that for every 10°C drop in temperature, systolic blood pressure rises by an average of about 5.7 mmHg. Since the elderly have weakened vascular elasticity, their blood pressure fluctuations are more significant, making them more susceptible to myocardial ischemia, angina, or even myocardial infarction. Therefore, when the elderly go out during the cold season, wearing a hat can effectively reduce vasoconstriction and blood pressure fluctuations, lowering the risk of cardiovascular diseases.

2. Preventing Cerebrovascular Diseases

Exposure to cold in the head can cause cerebral vasoconstriction and insufficient blood supply, increasing the risk of stroke. Research shows that the incidence of cerebrovascular diseases is significantly higher in winter than in summer. Wearing a hat helps maintain a stable brain temperature and reduces the likelihood of vascular spasms or ruptures. Especially for elderly individuals with arteriosclerosis or hypertension, keeping the head warm is a crucial measure for preventing cerebrovascular accidents.

3. Reduces the risk of respiratory diseases such as the common cold

The nasal mucosa serves as the first line of defense for the respiratory tract. Cold stimulation causes the blood vessels in the nasal mucosa to constrict, leading to reduced mucus secretion and weakened defensive functions. Wearing a hat can reduce the direct impact of cold air on the face and nasal cavity, helping to maintain the protective function of the mucosa. Clinical studies have confirmed that individuals who have the habit of wearing hats in winter have a significantly lower risk of contracting respiratory diseases such as the common cold.

4. Prevent frostbite and skin damage

Cold weather can easily lead to frostbite on exposed areas such as the ears and face. The skin on the ears is thin and has few blood vessels, making it highly susceptible to frostbite in low temperatures. Children are particularly prone to frostbite because their skin is thinner, yet their blood vessels are more abundant and their blood circulation is more active. Wearing a hat can effectively protect the ears and face, reducing the risk of frostbite. Additionally, hats prevent dust and microorganisms from sticking to the scalp, lowering the incidence of scalp infections and skin inflammation.

5. Scientific Warmth: It’s More Than Just Wearing a Hat

While wearing a hat is a crucial measure for staying warm in winter, scientific heat retention requires full-body coordination. The "onion layering method" is an ideal winter strategy: choose moisture-wicking and heat-generating thermal underwear for the base layer, fluffy and insulating garments for the middle layer, and a windproof and waterproof jacket for the outer layer. Additionally, the following points should be noted:

Foot warmth: As the folk saying goes, "cold starts from the feet," so keeping your feet warm is equally important. Choose cotton socks with good thermal properties and non-slip, warm shoes to prevent heat loss throughout the body caused by cold feet.

Neck warmth: The neck is a vital connection between the head and the torso, as well as a channel for heat loss. When going out, wear a scarf or a neck gaiter to protect the neck from direct exposure to cold winds.

Avoid overheating: While staying warm is important, excessive bundling can lead to profuse sweating, which actually increases the risk of catching a cold. You should add or remove clothing in a timely manner based on temperature changes and activity intensity to maintain a moderate level of warmth.

Indoor Warmth: Indoor temperatures in winter should be maintained between 20-22°C, with humidity controlled at 45%-60%. The elderly should pay particular attention to maintaining a stable indoor temperature and avoid frequent movement between environments with large temperature differences to reduce blood pressure fluctuations.

6. Hat Selection Recommendations for Special Groups

The Elderly: Seniors should choose lightweight, windproof, and warm hats made of materials such as wool or felt. The hat should cover the ears to prevent frostbite. Additionally, it should not be too tight to avoid restricting blood circulation. For elderly individuals with hypertension, wearing a hat can reduce the direct stimulation of cold air on blood vessels, lower the magnitude of blood pressure fluctuations, and decrease the risk of cardiovascular and cerebrovascular diseases.

Children: Parents should choose hats that meet safety standards, avoiding potential hazards such as detachable small parts or excessively long drawstrings. According to GB31701-2015 "Safety Technical Code for Infant and Children Textile Products," children's hats must pass hazardous substance testing (e.g., lead content ≤100ppm, phthalates ≤0.1%) and physical/mechanical performance tests (e.g., tension tests for small parts). Since children have a higher rate of heat loss through the head and thinner skin, materials with good warmth retention and breathability, such as wool or wool blends, should be selected. For infants and toddlers, greater emphasis should be placed on the softness and comfort of the hat to avoid applying pressure to the head.

Hair loss patients: Those suffering from hair loss may wear hats, but should choose breathable materials such as cotton, linen, or other natural fibers, while avoiding synthetic or non-breathable materials. The size of the hat is also crucial; ensure it is not so tight that it compresses the scalp, which could impair blood circulation. In hot weather, hats should be changed frequently and the scalp kept dry to reduce oil buildup that could exacerbate hair loss.

Small Hat, Big Health

Wearing a hat in winter may seem simple, but it embodies profound health wisdom. Keeping the head warm is not only an effective means of resisting the cold but also a health barrier for preventing various diseases. For vulnerable groups such as the elderly and children, head warmth is even more critical. By scientifically selecting and using hats, one can effectively reduce heat loss from the head, maintain a stable body temperature, and lower the risk of colds, frostbite, and cardiovascular or cerebrovascular diseases.



In the cold winter months, let us develop the habit of wearing hats and prepare suitable headwear for our families—especially the elderly and children—to build a collective defense for our health. After all, health is life's greatest wealth, and prevention is better than a cure. A proper hat can be a vital weapon in safeguarding your well-being.